Field
Exemplary embodiments of the present invention relate to a method of fabricating a light emitting device and, more particularly, to correction of color coordinates (or color temperature) of a light emitting device.
Description of the Background
Light emitting devices using a light emitting diode as a light source may be widely used in various fields due to advantages of low power consumption and long lifespan. Particularly, since the light emitting device may realize a mixed color, that is, white light, through combination of a light emitting diode and phosphors, the light emitting device may be used as a backlight source of a liquid crystal display and as various kinds of light sources for illumination.
A plurality of light emitting diode chips may be fabricated from a single wafer through the same process, and phosphors may be coated onto the light emitting diode chips at wafer level or chip level, or contained in a molding resin at package level and disposed on the light emitting diode chips. A color of certain color coordinates may be realized by mixing light emitted from the light emitting diode chip with light emitted from the phosphors. Thus, combinations of light emitting diode chips and phosphors may be determined so as to realize desired color coordinates during fabrication of a light emitting device.
Light emitting devices may be produced by the same process described above. For example, a number of light emitting diode chips having the same characteristics may be produced by the same process, and a molding resin containing the same kind and concentration of phosphors may be deposited on these light emitting diode chips. Since these light emitting devices may be produced by the same process so as to exhibit desired color coordinates, these light emitting devices may be expected to exhibit the same color coordinates. However, a process margin occurring in each process step may cause dispersion of color coordinates even though the light emitting devices are produced through the same process.
FIG. 1 is a graph depicting distribution of color coordinates of light emitting devices produced through the same process.
Herein, the graph shows distribution of color coordinates of a plurality of light emitting devices produced using blue light emitting diode chips and yellow phosphors. Rectangular boxes on the color coordinates indicate target ranges of color coordinates represented by bin codes.
Since a single kind of yellow phosphors is used, the light emitting devices may exhibit dispersion of yellow color coordinates over a region where blue color coordinates are relatively strong. Among the light emitting devices having such a distribution of color coordinates, light emitting devices within target bin codes may be chosen as good products and other light emitting devices are discarded as defective products.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form any part of the prior art nor what the prior art may suggest to a person of ordinary skill in the art.